1. Field of the Invention
The invention relates to a flange connection for round waveguides.
2. Discussion of Background
In connection with fusion research, the generation and the guidance of high-power microwaves are highly important since electromagnetic radiation can be used for heating the plasma. In this connection, frequencies within the range of some GHz to some hundred GHz are preferably used. Correspondingly, the required over-dimensioned waveguides have transverse dimensions of a few dozen to some centimeters. They are frequently circular in cross-section.
In principle, a waveguide has the task of conducting the electromagnetic waves from the location where they are generated to the location where they are used and to do that, if possible, without changing the type and intensity of the waves. The extent to which a waveguide can fulfill its task essentially depends on how constant its cross-section is. Abrupt changes in the cross-section, such as mainly occur when waveguides are connected at the front ends, lead, for example, to mode conversion and have a particularly disturbing effect. This is why it is important that the production tolerances of the waveguides are as small as possible (for example with respect to their cross-sectional shape) and that they are coaxially connected with high accuracy.
For coupling round waveguides, a flange connection is known from ISO Standard, publication 154-4, "Flanges for wave guides". In this arrangement, flanges are attached to the ends of the waveguides, for example by soldering, which are pressed against one another by two meshing toothed rings which are slipped over the flanges and are screwed against one another.
The great disadvantage of this flange connection lies in the fact that it is not possible to achieve coaxiality of the two waveguides with sufficient accuracy. Furthermore, the construction of this flange connection is cumbersome and its component parts are heavy and expensive. Finally, there are also problems in soldering on a flange.